This packet of 13 learning modules on hydraulics is 1 of 6 such packets developed for apprenticeship training for millwrights. Introductory materials are a complete listing of all available modules and a supplementary reference list. Each module contains some or all of these components: goal, performance indicators, study guide (a check list of steps the student should complete), a vocabulary list, an introduction, information sheets, assignment sheet, job sheet, self-assessment, self-assessment answers, post-assessment, instructor post-assessment answers, and a list of supplementary references. Supplementary reference material may be provided. The 13 training modules cover levers; transmission of force; symbols; basic systems; pumps; pressure relief valve; reservoirs; directional control valve; cylinders; forces, area, and pressure; conductors and connectors; troubleshooting; and maintenance. (YLB)